Invalidity Patent search also known as ‘knock out’ patent search. This search is conducted to invalidate the independent claims of competitors. If a invalidate claims get invalidate, the dependant claims automatically gets invalidate. It is a prior art search done after a patent has been issued.

The most usual cause of invalidating a patent is its power to abstract one’s commercial activities. It is mainly done by the defendants in case of patent infringement. It is basically research of patent where there is already litigation and a case against the patent has been filed to invalidate the patent application.


  1. Validity Search determining prior inventor ship
  2. Validity Search determining rights to a technology
  3. Validity Search determining to cut down competition
  4. Validity Search determining patent strength for licensing negotiation.

In case of Invalidity search, it is done on both Patent database as well as Non- Patent Database. The search is done on a global basis as novelty and non-obviousness are the criteria to be examined in such cases.


  1. Advance keyword search
  2. Citation search
  3. Inventor based search
  4. Assignee based search
  5. Logical search, etc.

Invalidity patent search is done on the request of the Company or an entity, to cut down competitors by invalidating the application. It is mainly conducted by the professional patent researcher. Based on the Patent Invalidity Search. Patent attorney prepares a report known as ‘Patent Invalidity Search Report’ [PISR]. This report acts as evidence when a patent infringement case is filed, to proof that the application should not be granted.